The principal long-range goal is the development of methods for the total synthesis of a biologically functional gene and to understand molecular mechanisms of gene control and expression. The total research involved in this program can be categorized as follows: (1) Further development of the chemical methods for the synthesis of deoxyribonucleotides. (2) Accomplishment of the total synthesis of a biologically functional gene during the past year now opens new doors to intensive studies of the molecular mechanisms as listed below: a. Mechanism of the initial recognition of the promoter region by the RNA polymerase. b. Formation of the stable DNA-RNA polymerase complex. c. The initiation of transcription by the RNA polymerase. 3. Synthesis of a varity of promoters with carefully designed alterations in nucleotide sequences will be used to study the transcription mechanism. (4) Studies of structure-function relationships in the tRNA region. New opportunities for these studies are again made possible by our ability to manipulate the gene structure in completely defined ways. (5) In vivo studies of the totally synthetic bacterial tRNA gene. Studies will be performed to demonstrate suppression of the amber mutation in an E. coli mutant by the synthetic gene. (6) Studies of the DNA-membrane interaction in bacterial and mammalian synthesis. (7) Studies of the DNA-protein interactions using enveloped viruses such as PM2, vesicular stomatitis virus (V.S.V.) and sindbis virus. BIBLIOGRAPHIC REFERENCES: Nucleotide Sequences at the Two Ends of the E. coli Tyrosine tRNA Genes and Studies on the Promoter. T. Sekiya, T. Takeya, R. Contreras, H. Kupper, H.G. Khorana and A. Landy in RNA Polymerase, pp. 455-472, Ed. R. Losick and M. Chamberlin, Cold Spring Harbor Laboratory, 1976. The Nucleotide Sequence in the Promoter Region of the Gene for an E. coli Tyrosine Transfer Ribonucleic Acid. T. Sekiya, M. J. Gait, K. Norris, B. Ramamoorthy and H.G. Khorana (1976), J. Biol. Chem. 251, 4481.